When I put my 1.8T through it's MOT early this year, it just about passed the emissions and the tester had to run the engine for a good 10 minutes before the emissions where low enough for it to scrape through. I also checked the MOT history on the car and it's failed the last few MOT's on emissions, but passed the retest (Somehow)! So the cat & manifold was replaced today. I managed to get a new cat genuine cat from ebay for just over £100 and I got a manifold for £15. One thing to note was the manifold was from a B6 1.8T & the cat had a part number which indicates it was only for a quattro version of the 1.8T. However both fitted perfectly without any modifications required. When I ripped off the old cat I found a completely empty cat, the dam thing had been through a decat, so if anyone want a free decat, cat! then then send me a PM, the only cost would be the postage. However you may find it difficult to pass the emission tests in the future.